This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A351658 #6 Feb 18 2022 03:03:45
%S A351658 1,-1,0,2,3,-8,-61,-134,567,6908,29631,-33857,-1624011,-13579197,
%T A351658 -42493684,449043601,8591509012,71167884338,153434398957,
%U A351658 -5188374785607,-95914651874891,-882652244738780,-1819090127593647,96780404956817315,2051640887011218601
%N A351658 G.f. A(x) satisfies: A(x) = 1 - x * A(x/(1 - x)^2) / (1 - x).
%F A351658 a(0) = 1; a(n) = -Sum_{k=0..n-1} binomial(n+k-1,n-k-1) * a(k).
%t A351658 nmax = 24; A[_] = 0; Do[A[x_] = 1 - x A[x/(1 - x)^2]/(1 - x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
%t A351658 a[0] = 1; a[n_] := a[n] = -Sum[Binomial[n + k - 1, n - k - 1] a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 24}]
%Y A351658 Cf. A000587, A125273, A351659.
%K A351658 sign
%O A351658 0,4
%A A351658 _Ilya Gutkovskiy_, Feb 16 2022